What is the difference between weathering steel and ordinary steel?

BBN Group is able to supply hot-rolled weathering steel 09CuPCrNi-A, Q450NQR1, hot-rolled weathering steel SPA-H, hot-rolled weathering steel B480GNQR, hot-rolled weathering steel Q345NQR2, Q355GNHD, Q355NH atmospheric corrosion resistant steel, hot-rolled weathering steel 09CuP; cold-rolled weathering steel 05CuPCrNi, cold-rolled weathering steel SPA-C, cold-rolled weathering steel Q310NQL2, cold-rolled weathering steel Q310GNH with high quality.

Weathering steel is considered the strongest material, and its resistance to atmospheric corrosion is 4 to 8 times that of ordinary low carbon steel. A unique feature of weathering steel is that due to exposure to the outdoors, they will form a thin brown patina whose appearance, composition and structure are different from other types of rust. During continuous exposure to moisture and dryness, the patina will turn orange and then reddish brown over time. After one year of exposure, the bronzer will turn dark brown, especially in urban environments.
Although weathering steel is a durable and strong material, exposure of weathering steel to extremely corrosive environments (such as coastal and tropical coastal areas) may cause material damage and failure.